Cathode ray tube with predetermined character shaped beam arrangement means



J. T. M NANEY 3,329,858 CATHODE HAY TUBE WITH PREDETERMINED CHARACTER SHAPED BEAM ARRANGEMENT MEANS Filed Sept. 4. 1964 2 SheetsSheet 1 July 4, 1967 NQE ,//v// Y \a Q@ mm m mm; .\.m U i 1 B mwm H H H fi 1 EJ QK m mm July 4, 1967 J. T. M NANEY 3,329,858

CATHODE RAY TUBE WITH PREDETERMINED CHARACTER SHAPED BEAM ARRANGEMENT MEANS Filed Sept. 4, 1964 2 Sheets-Sheet 2 INVENTOR.

mw OE m United States Patent Office 3,329,858 Patented July 4, 1967 ABSTRACT OF THE DISCLOSURE The present invention utilizes novel means in a cathode ray tube for presenting information in the form of characters, such as letters, numerals, etc., that may be used for viewing or record making purposes. These means include the use of a pair of aperture masks supported in the path of an electron beam in the tube, one mask containing a plurality of arrays of character shaped arrangements of apertures and the other having a plurality of apertures uniformly arranged therein and related, respectively, to predetermined portions of the character shaped arrangements of apertures in the one mask.

The character shaped arrays of apertures occupy the same general area of the one mask which, when exposed to the beam of electrons, will provide a plurality of arrays of individual secondary beams that overlap one another in the general area. An aperture of each such array, therefore, falls within one of a plurality of sub-areas within the general area, and each aperture of the other mask is related to one of these sub-areas and which is used as a beam selecting aperture insofar as its related sub-area and the apertures therein are concerned.

Beam deflection means are used in combination with the aperture masks to control the direction that electrons will follow during passage from one mask to the other and, therefore, to control the particular beam arrangement to be passed through the pair of masks. Immediately following the masks in the tube there is a focusing lens for controlling imaging and size conditions of the character shaped beam arrays at the surface of a target area in the tube. This lens is then followed by a post deflection means for positioning the arrays on the target.

This invention relates to cathode ray tube data display devices and more particularly to such cathode ray devices wherein a predetermined amount of information is stored and selectively displayed for viewing or recording purposes. Cathode ray tube devices which adequately represent the type of device to which I refer is disclosed in my US. Patent No. 2,761,988, and also, for the purpose of exemplifying still further, in my US. Patent No. 2,811, 668.

In devices of the type set forth in the above patents individual forms of information, such as letters, numerals, symbols, etc., are arrayed in a system of Cartesian coordinates and allowed to function as individual electron beam shaping areas. Usually electron beams from these areas are then serially projected on a viewing screen of such a device. A requirement in the fabrication of these types of cathode ray tubes is to limit the arrangement of a matrix of information bearing characters to a relatively small area in order to minimize the effects of spherical aberrations on the registration of characters as they appear on the viewing screen. In meeting this requirement it is therefore necessary for each character in the matrix to be correspondingly small which, of course, presents a secondary problem, namely, the ability to display characters having a high order of resolution or display quality.

The present invention, therefore, is designed to provide a beam forming means which is an improvement over the above matrix arrays of individual beam forming character shaped areas.

It is an object of this invention to provide an information generator which allows the formation of individual characters, or other forms of data, to take place on the optical axis of a cathode ray tube, therefore, avoiding the effects of spherical aberrations.

A further object is to provide an information generator which is inherently capable of providing a high order of resolution in the display of letters, numerals, symbols, etc.

Still another object of this invention is to provide a relatively simple and eflicient means of displaying information within a cathode ray tube.

Other objects and advantages will appear hereinafter as a description of the invention proceeds.

The novel features that are considered characteristic of :this invention are set forth with particularity in the appended claims. The invention itself, both as to its originality and method of operation, and additional objects and advantages, will best be understood from the following description when read in connection with the accompanying drawings in which: I

FIGURE 1 is a sectional view of a cathode ray device including the beam forming and projection means of this invention;

FIGURE 2 represents a detail of the masking means of the invention;

FIGURE 3 is a diagram of another embodiment of the information retrieval beam deflection system of the invention;

FIGURE 4 is a detail of the masking means utilized in the description of the invention;

FIGURE 5 represents a section of the information storage mask; and

FIGURE 6 represents a section of the information selection aperture mask.

The cathode ray device of FIGURE 1 is shown to include a somewhat conventional evacuated envelope 20, having an electron target area 30 at one end and electron ray generating means 40 at the opposite end. The electron masking means or unit 50 is disposed along the optical axis 51 of the device and intermediate the target area 30 and the generating means 40. Also disposed along the axis 51, intermediate the unit 50 and the generating means 40, there is an electron beam deflection means, exemplified as being a magnetic deflection yoke 52. On the opposite side of the unit 50 there is an electron focusing means or electrostatic lens 53, and immediately following lens 53 there is a second deflection means, also exemplified as being a magnetic deflection yoke 54. Associated with the generating means 40 there is an additional system of lens elements 55 for controlling the size and parallelism of the electron beam 56 in the process of being projected toward the unit 50. 1

In FIGURE 2 the unit 50 is illustrated as comprising first and second masks, 57 and 58, and supported in a predetermined spaced apart relationship by support means 59. The mask 57 may be referred to as the information storage mask, and the mask 58 may be referred to as the information selection aperture mask. A plan view of portions of these masks is shown in FIGURES 5 and 6, The mask 57 is shown to be divided into a plurality of coordinately arranged rows and columns of sub-areas 60, 61, 62, etc., and each area is designed to contain a predetermined number and a predetermined array of apertures therein. And the entire system of sub-areas will therefore contain a plurality of informative arrays of apertures overlaying one another. The mask 58 is shown to contain a plurality of apertures coordinately arranged therein to correspond with the arrangement of sub-areas in the mask 57. One sub-area 60, for example, of mask 57 3 is shown bounded by lines 21-22 and 41-42, and an aperture 70 of mask 58, within an area bounded by lines 11-12 and 31-32, will be designed to correspond with one another in the unit 50. And the sub-area 61 will correspond with the aperture 71 of mask 58, etc. in the assembled unit 50.

Referring now to a single sub-area 60 of mask 57, and the aperture 70, including the latters sub-area bounded by lines 11-12 and 31-32, in FIGURE 4 they are again shown as they will be related in the unit 50. Each of these sub-areas are again divided into a system of Cartesian coordinates, each containing an array of sixty-four crossover or intersecting lines. The aperture 70 within its subarea 70 purposely, does not coincide with any of the intersecting lines. Within the sub-area 60, however, there are, for example, three apertures coinciding respectively with the intersecting lines l-h, 6-g and 8-d, each representing sub-area 60 apertures of three overlapping informative arrays. Depending upon the characteristics of these three overlapping arrays the remaining sub-areas 61, 62, etc., may contain apertures at similar, or some other, intersecting lines thereof. Although there are but eight sub-areas illustrated in the mask 57 of FIGURE 5, and but eight apertures illustrated in the mask of FIG- URE 6, a complete unit may have as many as 900, or more, sub-areas and selection apertures, depending upon the display detail requirements of the informative arrays. The division of each sub-area into sixty-four line intersections indicates that such a unit 50 will contain up to sixty-four separate informative arrays, or characters such as letters and numerals.

When the electron masking means 50 is being used in a cathode ray device such as that illustrated in FIGURE 1, it may be disposed along the optical axis 51 so that the mask 57 intercepts the electron beam 56 initially and then allows minor electron streams, through the apertures therein, to reach the second mask 58. Or, the position of the unit 50 may be reversed so that the electron beam 56 reaches the mask 58 first and then passes minor electron streams through the apertures therein onto the mask 57. The operating principles of the unit 50 in either case are similar, however, the preferred position of the two is to have the mask 57 facing the electron beam 56, and this is the manner in which the discussion of the operation of the unit 50 will continue.

When the beam 56 as illustrated in FIGURE 1 is superimposed upon the masking means 50 the beam 56 will be of the size necessary to enter all of the apertures in the mask 57 simultaneously, and all of the rays therein will be following a path in parallel. These conditions will be provided for, of course, by the operating characteristics of the electron projection means 40 and 55, in combination with voltages connected thereto from the voltaage unit. However, only at predetermined angles in relation to the optical axis 51 will portions of the beam 56 enter apertures 70, 71, 72, etc., of mask 58 from apertures in mask 57. This is best illustrated in FIGURE 4, wherein a group of parallel rays 80, 81 and 82, of the electron beam 56, are entering apertures at the line intersections l-h, 6-5 and S-d, respectively. The rays 80, 81 and 82 are also understood to be parallel with the axis 51 and under these conditions will succeed only in reaching the intersections of lines l-h, 6-g and 8-d on the mask 58. Under one set of horizontal and vertical beam deflection angles the ray 80 will enter the aperture 70; under another set of horizontal and vertical beam deflection angles the ray 81* will enter the aperture 70; and under still another set of horizontal and vertical beam deflection angles the ray 82 will enter the aperture 70.

Since there are sixty-four intersections at which apertures may be placed in the mask 57 sub-areas, the optical alignment of sixty-four such apertures with the selection apertures in the mask 58 will correspond to sixty-four different sets of horizontal and vertical beam deflection angles. For each set of horizontal and vertical beam deflection angles, therefore, a different informative array of minor electron streams will be exposed to the arrangement of selection apertures in the mask 58. The invention is not limited, of course, to the use of the sixty-four intersections at which apertures may be placed in the mask 57 sub-areas. There may be more, or less, than the figure sixty-four, depending entirely on application requirements of the invention.

The apertures in both masks, 57 and 58, may have a dimension of 0.001, or less, in diameter, and the mask material may be of the various materials which lend themselves to chemical milling, or chemical etching, such as copper, Phosphor bronze, silver, stainless steel, etc. The thickness of the mask material may be 0.001, and in some cases more or less than this particular thickness. When the masks, 57 and 58, are supported in their spaced apart relationship the spacing between them may be, for example, 0.2. The apertures in the mask 57 will be placed therein as a function of the information they represent, however, the line intersections 1-a, 2-a, 3-a, etc. at which the apertures will be placed may represent, for example, spacings of 0.002". The apertures in the mask 58, therefore, will be placed on center-to-center spacings of 0.016", and if such an array of apertures is equal to 30x30 or 900 apertures, then the combined array will be contained in an area of about 0.48" x 0.48. This latter area dimension would represent the maximum size that informative arrays of minor electron streams, which may be in the form of letters, numerals, etc., will be presented at the surface 58 of the unit 50 as illustrated in FIGURE 1.

Referring once again to FIGURE 1, the focusing lens 53 will be designed to control the imaging and size conditions, on the target area 30, of the informative arrays of electrons appearing at the surface 58 of the unit 50. In addition to effecting a first crossover 66 in the process of effecting imaging and size conditions of the beam 56*, the lens 53 may also be utilized in providing a second crossover at the plane of deflection 67 to minimize post deflection distortions of the beam 56 in the target area 30. Since all informative arrays of electrons appearing at the surface 58 will have been superimposed one upon the other, and therefore all capable of being aligned with a common optical axis of the display device, the effects of spherical aberrations on the registration of such images in the target area 30, as in the case of prior art display devices, will be at a minimum.

Although it has been hereinbefore set forth that the electron beam 56 is designed to essentially flood all of the apertures in the mask 57 simultaneously, the invention is not to be limited in this regard. As illustrated in FIG- URE 3, for example, through the use of two independently controlled deflection systems, such as deflection yokes 91 and 92, a somewhat smaller diameter electron beam 86 may be used to scan the unit 50 to provide the desired results. The first yoke 91 is used to deflect the beam 86 away from the common axis 51 in cooperation with the second yoke 92 in the establishment of the beam angle necessary to select a desired informative array in the unit 50. In each of the embodiments the selection of informative arrays of electron streams from the mask 57 will be a function of the path along which a cathode ray is directed, and in each case such paths will correspond to an angular approach of the ray toward the unit 50 with respect to the optical axis 51 of the cathode ray device. The unit 50, of course, will be made to coincide with a plane normal to the axis 51.

In the process of informative array selection and post deflection the necessary control voltages will be obtained from an appropriate source, or a control unit 87. From the above description of the invention it will be noted that the selection angle requirements are relatively small and, accordingly, electron beam selection power requirements will be small. This, of course, is an important factor in display tubes of this type. And it is also to be understood that electrostatic means of beam deflection may be used in place of the magnetic means indicated, such as the yokes 52, 54, 91 and 92.

Techniques for chemically milling the apertures in the masks of the unit 50 are well known in the arts, and photographic methods of accurately locating the apertures in these masks are also well known. In preparing the masking means of this invention, attention is called to the technique set forth in US. Patent No. 2,969,531 for cating, very precisely, the apertures in the information storage mask 57.

Although I have limited myself to the showing of certain embodiments of the invention, it should be understood by those skilled in the arts that the invention is not limited in this regard since many of the other embodiments embracing the general principles and constructions hereinbefore set forth may be utilized and still be within the ambit of the present invention.

The particular embodiments of the invention illustrated and described herein is illustrative only, and the invention includes such other modifications and equivalents as may readily appear to those skilled in the arts, and within the scope of the appended claims.

I therefore claim:

1. In a cathode ray tube having an electron beam generator for providing a primary beam of electrons and means for directing said beam along a predetermined path, including:

(a) means for utilizing said beam in providing a plurality of arrays of individual secondary beams of electrons wherein each array of said beams comprises a formation of individual beams representative of a predetermined character shaped arrangement thereof;

(b) said last stated means including a combination of at least two masks each having electron beam limit ing apertures therein and supported in the path of electrons from said generator;

(c) one of said masks having a plurality of individual arrays of apertures in a same general area thereof for providing said plurality of arrays of individual secondary beams and wherein an aperture of each said individual array of apertures falls within one of a plurality of sub-areas within said general area whereby said individual arrays of apertures comprise character shaped arrangements of apertures overlapping one another within said general area; and

((1) another of said masks having a plurality of apertures wherein each of said apertures is related to a sub-area of said one mask so as to be optically related to apertures of but a portion of a character shaped arrangement of said individual arrays of apertures.

2. The invention as set forth in claim 1 additionally including:

(e) a target area; and

(f) electron focusing means disposed along the optical axis of said tube intermediate said masks and said target area.

3. The invention as set forth in claim 2 additionally including:

(g) post-deflection means disposed along said axis intermediate said focusing means and said target area for directing each of said character shaped arrangement of beams toward predetermined positions within said target area.

References Cited UNITED STATES PATENTS 2,530,538 11/1950 Rack 178-435 2,761,988 9/1956 McNaney 313-82 X 2,826,716 3/1958 McNaney 31513 JOHN W. CALDWELL, Acting Primary Examiner.

DAVID G. REDINBAUGH, Examiner.

T. A. GALLAGHER, R. K. ECKERTJR Assistant Examiners. 

1. IN A CATHODE RAY TUBE HAVING AN ELECTRON BEAM GENERATOR FOR PROVIDING A PRIMARY BEAM OF ELECTRONS AND MEANS FOR DIRECTING SAID BEAM ALONG A PREDETERMINED PATH, INCLUDING: (A) MEANS FOR UTILIZING SAID BEAM IN PROVIDING A PLURALITY OF ARRAYS OF INDIVIDUAL SECONDARY BEAMS OF ELECTRONS WHEREIN EACH ARRAY OF SAID BEAMS COMPRISES A FORMATION OF INDIVIDUAL BEAMS REPRESENTATIVE OF A PREDETERMINED CHARACTER SHAPED ARRANGEMENT THEREOF; (B) SAID LAST STATED MEANS INCLUDING A COMBINATION OF AT LEAST TWO MASKS EACH HAVING ELECTRON BEAM LIMITING APERTURES THEREIN SAID SUPPORTED IN THE PATH OF ELECTRONS FROM SAID GENERATOR; (C) ONE OF SAID MASKS HAVING A PLURALITY OF INDIVIDUAL ARRAYS OF APERTURES IN A SAME GENERAL AREA THEREOF FOR PROVIDING SAID PLURALITY OF ARRAYS OF INDIVIDUAL SECONDARY BEAMS AND WHEREIN AN APERTURE OF EACH SAID INDIVIDUAL ARRAY OF APERTURES FALLS WITHIN ONE OF A PLURALITY OF SUB-AREAS WITHIN SAID GENERAL AREA WHEREBY SAID INDIVIDUAL ARRAYS OF APERTURES COMPRISE CHARACTER SHAPED ARRANGEMENTS OF APERTURES OVERLAPPING ONE ANOTHER WITHIN SAID GENERAL AREA; AND (D) ANOTHER OF SAID MASKS HAVING A PLURALITY OF APERTURES WHEREIN EACH OF SAID APERTURES IS RELATED TO A SUB-AREA OF SAID ONE MASKS SO AS TO BE OPTICALLY RELATED TO APERTURES OF BUT A PORTION OF A CHARACTER SHAPED ARRANGEMENT OF SAID INDIVIDUAL ARRAYS OF APERTURES. 